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1 /* |
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2 * Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved. |
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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4 * |
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5 * This code is free software; you can redistribute it and/or modify it |
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6 * under the terms of the GNU General Public License version 2 only, as |
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7 * published by the Free Software Foundation. |
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8 * |
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9 * This code is distributed in the hope that it will be useful, but WITHOUT |
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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12 * version 2 for more details (a copy is included in the LICENSE file that |
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13 * accompanied this code). |
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14 * |
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15 * You should have received a copy of the GNU General Public License version |
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16 * 2 along with this work; if not, write to the Free Software Foundation, |
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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18 * |
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19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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20 * or visit www.oracle.com if you need additional information or have any |
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21 * questions. |
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22 * |
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23 */ |
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24 |
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25 #include "precompiled.hpp" |
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26 #include "classfile/javaClasses.hpp" |
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27 #include "memory/referencePolicy.hpp" |
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28 #include "memory/universe.hpp" |
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29 #include "runtime/arguments.hpp" |
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30 #include "runtime/globals.hpp" |
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31 |
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32 LRUCurrentHeapPolicy::LRUCurrentHeapPolicy() { |
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33 setup(); |
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34 } |
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35 |
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36 // Capture state (of-the-VM) information needed to evaluate the policy |
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37 void LRUCurrentHeapPolicy::setup() { |
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38 _max_interval = (Universe::get_heap_free_at_last_gc() / M) * SoftRefLRUPolicyMSPerMB; |
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39 assert(_max_interval >= 0,"Sanity check"); |
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40 } |
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41 |
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42 // The oop passed in is the SoftReference object, and not |
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43 // the object the SoftReference points to. |
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44 bool LRUCurrentHeapPolicy::should_clear_reference(oop p, |
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45 jlong timestamp_clock) { |
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46 jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p); |
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47 assert(interval >= 0, "Sanity check"); |
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48 |
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49 // The interval will be zero if the ref was accessed since the last scavenge/gc. |
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50 if(interval <= _max_interval) { |
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51 return false; |
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52 } |
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53 |
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54 return true; |
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55 } |
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56 |
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57 /////////////////////// MaxHeap ////////////////////// |
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58 |
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59 LRUMaxHeapPolicy::LRUMaxHeapPolicy() { |
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60 setup(); |
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61 } |
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62 |
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63 // Capture state (of-the-VM) information needed to evaluate the policy |
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64 void LRUMaxHeapPolicy::setup() { |
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65 size_t max_heap = MaxHeapSize; |
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66 max_heap -= Universe::get_heap_used_at_last_gc(); |
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67 max_heap /= M; |
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68 |
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69 _max_interval = max_heap * SoftRefLRUPolicyMSPerMB; |
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70 assert(_max_interval >= 0,"Sanity check"); |
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71 } |
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72 |
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73 // The oop passed in is the SoftReference object, and not |
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74 // the object the SoftReference points to. |
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75 bool LRUMaxHeapPolicy::should_clear_reference(oop p, |
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76 jlong timestamp_clock) { |
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77 jlong interval = timestamp_clock - java_lang_ref_SoftReference::timestamp(p); |
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78 assert(interval >= 0, "Sanity check"); |
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79 |
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80 // The interval will be zero if the ref was accessed since the last scavenge/gc. |
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81 if(interval <= _max_interval) { |
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82 return false; |
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83 } |
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84 |
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85 return true; |
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86 } |